Lack of effect of indomethacin on ordered growth of the femur in rats.

The effect of indomethacin on ordered growth in length and width of the femur was studied in 48 adolescent rats given 2 mg/kg/day of the drug, a regimen previously shown to inhibit fracture healing. The animals were given either indomethacin suspension, or the vehicle alone, orally for 6 weeks. All the animals tolerated the treatment well. During drug treatment the femur distal to the intertrochanteric crest grew about 7 mm in length. Indomethacin plasma levels were about 1 microgram/ml in the indomethacin-treated animals. Indomethacin did not inhibit ordered growth in either length or width. This indicates that indomethacin does not inhibit the normal homeostasis of the skeletal system in adolescent rats.